<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body>
        <img src="pic/ad.jpg" class="ad">
        <script type="text/javascript">
            var ad = document.querySelector('.ad');
            setTimeout(function() {
                ad.style.display = 'none';
            }, 5000);
        </script>
    </body>
</html>
